Over the past 15 years, manufacturers have developed numerous high-solids, fast-curing coating systems they claim will resist sulfuric acid in sewers and wastewater treatment plants. However, field performance of these coatings has varied greatly. In 1983, the County Sanitation Districts (CSD) of Los Angeles County launched a testing program simulating actual field conditions to identify coating systems that would bond strongly to concrete and provide the required sulfuric-acid resistance. To date, CSD has tested 78 different protective systems, but only 27 have successfully completed one year of evaluation.